High precision remote time transfer technology finds valuable and important applications in the fields of satellite navigation, scientific research and measurement, aeronautics and astronautics, deep space exploration, telecommunication, power industry, and finance. With the improvement of atomic clock and increased demand for time synchronization precision in various applications, requirement for time transfer precision gets more demanding. In high precision time transfer, it is generally required to implement synchronous transfer of one pulse per second (1 PPS) signals, time message and control message by means of encoding. Encoding and decoding method is one of the main factors in deciding time transfer precision, which again depends on the transfer precision of the front-edge of pulse per second signals. Two-way satellite time and frequency transfer (TWSTFT) implements remote time transfer at sub-nanosecond level via pseudo-random spread spectrum coding. However, the scheme thereof requires complicated coding modulation and decoding of modulated codes, and is therefore costly. IRIG-B is an internationally adopted standard scheme for time transfer encoding. Its upsides include simple implementation, large volume of messages, standard interfaces, and low cost. However, TRIG-B transmits codes just at the speed of 100 bit/second and requires modulation onto high speed carrier for remote transmission. Moreover, as it carries no time interval message, additional communication channels are required to transmit time interval messages for two-way time comparison adopting the time code. Further, optical fiber has low consumption and high bandwidth, and its potential for implementing higher precision time transfer has attracted great attention. Nevertheless, design of prior art time codes is directed at space channels and electric cables. Improvement and optimization thereof based on features of optical fiber transmission systems is in need.